Mario officially went portable with Super Mario Land on the Gameboy in 1985. The Gameboy’s LCD was only able to display 4 shades of grey over a greenish tinted screen. Super Mario Land was designed by Gunpei Yokoi as a way to prove that his Game Boy could play a game every bit as fun and complex as the original NES could.
Unlike later Gameboy games, Yokoi chose to scale down the amount of pixels so that mario had a similar amount of room to play on TV screen. Later games chose to use larger, more detailed sprites for the characters at the cost of a more restricted level design.
